User interfaces may include content regions that display content, and control regions that display controls. For example, an email application may have a user interface that includes a content region that displays the content of an email, as well as a control region that includes reply, forward, and delete buttons. A web browser may display the content of a web page in a content region, and may display, in a control region, a navigation bar for allowing the user to navigate web pages or to determine information about a particular web page.
Applications typically display controls adjacent to content. When a user interface includes a large number of controls, the display of one or more control regions may overwhelm the small screen of a mobile device. To overcome this problem, traditional mobile device applications require the user of the mobile device to interact with the mobile device application before controls are shown. This approach, however, requires the user to be aware that the control region exists. Furthermore, once the control region is displayed, the small screen of a mobile device may become, and may remain, similarly overwhelmed.